SLB-50B-70N 50.0 mm Dia. x -69.5 mm FL; Double-Concave Lens Uncoated

The SLB-50B-70N is a high-quality double-concave lens, sourced from the reputable optical component manufacturer, OptoSigma. This lens, with a base shape of a circle, is designed for use in a wide range of optical applications, thanks to its precise geometry and material properties.

The lens has a diameter of 50.0 mm and a center thickness of 3.0 mm, ensuring a substantial light-gathering capacity. The edge thickness is 11.9 mm, providing robustness and durability. The effective focal length (EFL) of this lens is -69.5 mm, indicating its double-concave nature, which is further confirmed by its radii of curvature, r1 and r2, at -72.66 mm and 72.66 mm, respectively. The back focal length (BFL) is -70.5 mm.

The lens is made of n-BK7 Schott, a popular optical glass due to its excellent optical properties, including a high Abbe number and low dispersion. This makes the lens suitable for use across a wide spectrum of wavelengths, with the specified wavelength being 546.1 nm.

Notably, this lens is uncoated, offering users the flexibility to apply their preferred coating based on their specific application requirements. However, it's essential to consider that uncoated lenses may have higher reflectivity, which could impact the overall system performance.